Signal



Nov. 20, 1934 g ADLER, :JR 1,981,577

S IGNAL Filed Sept. 28, 1934 v 2 fleets-Sheet 1 Nov. -20, 1934. c, A LER, JR

SIGNAL Filed Sept. 28, 1934 2 Sheets-Sheet 2 am 7526a Jr;

Patented Nov. 20, 1934 UNITED STATES PATENT OFFICE 3 Claims.

My invention relates to signals and more particularly signals applicable for railroad and street traflic control, although it will be understood that the invention may be practiced under other con- 5 ditions, as for example, in hospital signal system and exit indicators.

The primary purpose of the present invention is to incorporate in a signal a safety factor, that is to say, a means whereby an indication of a partial failure will be given before a complete failure of the system takes place and such partial failure will be indicated to an observer, while at the same time an operative signal indication will be maintained. In a construction of this character,

it is vital that the signal area be intensely illuminated not only prior to a partial failure but, of equal importance, thereafter.

Referring to the drawings,

Figure 1 is a side elevation of a lamp constructed in accordance with my United States Patent Figure 2 is a top view partly in section of a system employing a reflector and a lens or cover glass;

Figure 9 is a view similar to Figure 2 showing the manner in which certain of the light rays are reflected and bent or directed by the corrugations of the cover glass or lens;

Figure 4 is a sectional view partly broken away showing in detail the manner in which the direction of certain of the reflected light beams is altered by the corrugations of the lens or cover glass;

Figure 5 is a plan View of a modification looking at the inside of the cover of a signal housing;

Figure 6 is a sectional view of the construction shown in Figure 5;

Figure '7 is a diagrammatic view showing how the contrasting bright and dark areas appear 0 .when a failure occurs; and

Figure 8 is a front elevation showing diagrammatically the parallel positioning of the elongated filaments with relation to the corrugations of the cover glass or lens.

Figure 1 an electric lamp, in accordance with my Referring to the drawings, I have illustrated in of Figure 1 positioned in a signal system which includes a reflector 14, preferably of the parabolic type, and a cover glass or lens 15, the said lamp extending in axial relation to the cover glass and reflector. This cover glass or lens is provided with a plurality of vertically extending parallel flutes or corrugations 16. The filaments 12 are offset with relation to the focal point of the reflector but extend in parallel relation to the corrugations of the signal area as shown in Figure 8;

In Figure 3 I have illustrated diagrammatically the manner in which beams of light are reflected by the reflector 14 through the cover glass or lens '15. It will be noted, upon reference to Figure 3, and particularly to Figure 4, that, by reason of the offset relation of the filaments, certain of the beams are not reflected in parallel relation to each other and also reach the cover glass or lens at an angle thereto. By providing a corrugated lens and a reflector in association with the elongated offset filaments which latter are disposed parallel to the corrugations, such rays as shown are refracted by the cover glass or lens so as to be straightened and emerge from the cover glass or lens parallel to each other, and, are corrected due to the offset relation of the filaments.

Such a construction therefore assures that the signal area constituted by the cover glass or lens will be intensely illuminated, either when both filaments 12 are energized, and, of equal importance when there is a failure due to one filament burning out. Under the conditions of a failure, the remaining filament in cooperation with the'screen 13, will produce, as shown in -Figure 7, an intense partial illumination of the signal area maintaining the signal operative, and at the same time, a contrasting dark spot is presented on the signal area indicative of the failure- Referring to Figures 5 and 8, I have illustrated a construction employing a corrugated cover glass or lens 15 constituting a signal area and a preferably parabolic reflector 14, the illuminating means comprising a pair of lamps 20 with a screen 13 therebetween. The elongated filaments 21 of the lamps are offset with respect to the focal point of the reflector and are electrically connected in parallel; the filaments are also positioned in parallel relation to the corrugations in the manner illustrated in Figure 8. This structure is shown and described in my copending application Serial No. 614,817, filed June 1, 1932. The lamps extend vertically, i. e. parallel to the 11 cover glass as distinguished from the axial position of the lamp in Figures 2 and 3.

In either of the constructions shown, namely Figures 2-3 and 56, when one of the flalments burns out, there is presented on the signal area an intense bright area and a contrasting dark area both visible at a considerable distance and substantially as diagrammatically shown in Figure 7. As stated, the provision of the corrugated signal area with the offset filaments 12 or 21 disposed in parallel relation to the corrugations produces, as shown in Figure 3, an intense and complete illumination of the signal when each filament is energized in the normal operation of the signal, and when only one of the filaments is energized and the other is burned out there is produced an intense partial illumination and a dark spot both observable at a considerable distance, as shown in Figure 7. Briefly, the reflector and cover glass or lens cooperate with the oflset elongated filament or filaments in such a manner that a substantial percentage of the beams of light reflected by the reflector in nonparallel relation and at an angle to the signal area are utilized and not lost or wasted, i. e.

parallel relation and constituting a signal area,

a parabolic reflector, and electric lighting means comprising an elongated filament presented in substantially parallel relation to said corrugations and offset with respect to the focal point of the reflector, said reflector reflecting light from said filament through said cover glass or lens.

2. A signal comprising a lens or cover glass having corrugations arranged substantially in parallel relation and constituting a signal area, a parabolic reflector, and electric lighting means comprising elongated filaments and presented in substantially parallel relation to said corrugations, said filaments screened one from the other and offset relative to the focal point of said reflector, said reflector reflecting light from said filaments through said lens or cover glass and said lens or cover glass changing the direction of certain of the light beams whereby they are refracted by the glass or, lens in substantially parallel relation to each other.

3. A signal comprising a lens or cover glass having corrugations arranged substantially in parallel relation and constituting a signal area, a parabolic reflector, and electric lighting means comprising elongated filaments electrically connected in parallel and presented in substantially parallel relation to said corrugations, said filaments screened one from the other and offset relative to the focal point of said reflector, said reflector reflecting light from said filaments through said lens or cover glass and said lens or cover glass changing the direction of certain of the light beams whereby they are refracted by the cover glass or lens in substantially parallel relation to each other. i

' CHARLES ADLER, JR. 

